- Author: Mark Bolda
Local berry growers should take note that our in-house LBAM person, Neal Murray, notes the following in his twice monthly update tracking LBAM activity in the Monterey Bay area:
"We expect to see peak flight activity very soon. Continue vigilant scouting and monitoring for larvae. Mating disruption dispensers should already be in place and thorough scouting should be utilized to look for feeding larvae."
Link:
http://cesantacruz.ucanr.edu/files/157533.pdf
If you are an organic berry grower, you really should be following this advice and putting out the mating disruption dispensers, as your other options are limited. The dispensers work and are worth the while.
- Author: Mark Bolda
Just doing the usual weekend reading and came across this gem in The Economist:
Seems banana producers down south are facing serious challenges from two pathogenic fungi. One pathogen has become resistant to the fungicide complex used to control it and a strain of the other pathogen has overcome the resistance to it by the most widely planted banana variety.
Not that I would ever be happy about the travails of fellow agriculturists, but knowing that bananas are far and beyond the most consumed fruit by Americans (33 lbs/year well beyond the second place apples at 16 lbs/year), the big rise in price of bananas that this impending disease induced reduction in supply implies means an improved market for berries - which are pretty widely consumed in the USA already.
Interesting stuff.
- Author: Mark Bolda
Announcing a field lygus bug meeting. UCCE's Mark Bolda and Shimat Joseph and the CSC's Hillary Thomas will cover all aspects of lygus bugs in strawberries - when and where to look, proper sampling, identification of lygus and beneficials, control and use of tractor mounted vacuums.
Material will be presented in Spanish with translation to English and English with translation to Spanish.
Should be a good meeting- don't miss it!
- Author: Mark Bolda
Webinar on Organic Blackberry Production-- March 13
You are invited to take part in a webinar on "Organic Blackberry Production: Tips learned from an ongoing research study", presented by Bernadine Strik and Luis Valenzuela of Oregon State University and David Bryla of the USDA ARS in Corvallis, Oregon. The webinar takes place on March 13, 2014 at 2PM Eastern Time (1PM Central, 12PM Mountain, 11AM Pacific Time). Audience members will be able to type in questions for the speakers. The webinar is free and open to the public, but advance registration is required.
Register now at: https://www1.gotomeeting.com/register/363427577. Visit http://www.extension.org/pages/70279/organic-blackberry-production:-tips-learned-from-an-ongoing-research-study to learn more, including system requirements for participating.
- Author: Mark Bolda
Another short summary from the Fertility Short Course held by Tim Hartz and Stuart Pettigrove at UC Davis this past fall.
Calcium (Ca) has an important role in plant nutrition, but we tend not to pay too much attention to it because rarely is it an issue in berry health on the Central Coast. As outlined further on in this post, it's because we have so much of it already in our soils here.
Crop uptake of calcium is in the range of 100- 300 lb per acre, which means having a soil test like the one below with something around 5100 ppm has a potential supply of 10,200 lbs of Ca per acre (5100 PPM x 2 = 10,200 lbs/A) in the top 6” of soil apparently is well excess of what is needed.
Then again, we know that all the Ca removed in this ammonium acetate (NH4OAc) extraction is not all available to the plant because it can be tied up on soil particles, organic matter, colloids or precipitated out as Ca compounds.
A saturated paste analysis like the one on the left of the soil test below (circled in green) is the way to address what is really available to the plant. Results are most commonly given in meq/l, meaning milliequivalents per liter solution.
To get a feel for the Ca availability that we see on our saturated paste soil results, bear in mind that hydroponic solutions for greenhouse or substrate production, which are formulated for optimum crop growth and production, are 4-8 meq Ca/liter, and comprise 30-50% of the total cation meq. Comparing this ideal formulation with a survey (see link below) of representative crop production soils in coastal and central California which found of average of approximately 6.6 meq/liter Ca (assuming a 5:1 ratio soil solution/saturated paste and equivalent to 660 ppm Ca) and represented 55% of the cation milliequivalents. This amount, roughly calculated out, arrives at 600 lb Ca in soil solution. To reiterate from the above, crop removal is around 100-300 lb per acre, so this gives us a lot of confidence that we really have ample Ca around here for our berry crops.
Thinking through this to its practical application in the field, compared to the large amounts of calcium already available in our soils, fertilizer additions of calcium don't really add that much at all. For example, the “calcium kick” from a fertilizer like CAN-17 (12.3 lb/gal, 8.8 % Ca, so a 3 gal/A application simply adds 3.25 lbs of Ca/A - a mere drop in the pool of 600 lbs already there for the plant) isn't much of a kick at all.
Here is the excellent link discussing calcium availability in coastal and central California soils referred to in this post :
http://www.cdfa.ca.gov/is/docs/04-0701Hartz%2007.pdf